Transmission



No 20, 1945. A Y DODGE 2,389,186

TRANSMISSION Filed May 14, 1942 @ragga rotatable and slidable on cgected through a universal point to the output vure 2; and

atente Nov. 20, 1945 assalss TRANSMISSION g aaien Y. page.' Rockford, nl; Application May 14, 1942, SerialNo./442,955 y 10 Claims. (Cl. (l0-53) 'This invention relates to transmissions and more particularly to transmissionsof the uid displacement type.

One ofthe objects of the invention is to provide a transmission of the iiuid displacement type in which a portion of the input torque is transmitted directly through la iluid pump to the output shaft and iluid from the pump operates a motor-whose output torque is also transmitted to the shaft. In thisway the'motor vtransmits only the reaction torque of the pump rather than the full torque load and consequently a'-smaller motor lnaybeutilized.l y

Another object ofthe invention is to provide a transmission of the iluid displacement type which is fully automatic in operation. According to one feature-the transmission is primarily torque responsive although it may be additionally more or less responsive to speed. l Y

Another object of the invention is Ato provide a transmission oflthe Huid-displacement type in which the torque flow may be interrupted by venting the motor. Thus, the transmission embodies the functions of a clutch with the addition only ofa simple control valve.

Another object of the in a transmission oi' the uid which all of the parts rotate as a unit at Aa torque and speed ratio of one tcone. To accomplish this feature the reaction is taken by al one-way brake during torque multiplication, the brake overrunning as the ratios approach unity.

Still another object of the invention isv to provide a transmission offthe swash ,plate type in which the swash plate is eccentrically-mounted to be torque responsive and including a ring the swash plate and A further object of the invention is to provide a transmission including a gear` pump and .a

ention is to -provide displacement type inV swash plate type motor in which the motor car- 'I ries onli' the reaction of the output torque torque.

The above andl other of the invention will be apparent from the following description when read in connection with the accompanying drawing, inwhichtorque that is, -that part over and abovethe input tor and valve parts on the line xr of Figure 2 and the swash plate parts on the line yy of Fig- Figure 2 is a transverse of Figure l.

The transmissionv illustrated connects a driving shaft I to a driven shaft II and isof a type adapted for use in automotive vehicles. The driving 'shaft it is connected through a disc I2 section on the line 2 2 objects and advantages y againstleakage of iluid and which are connected as shown to the driven shaft. The spaces between the platesaround the gears may be illled by stop plugs to provide a `gear pump as is-well understood vin the art. The end plate I'I is formed with'a high pressure chamber I8 communicating with the gear teeth through pump outlet passages I9 and with a low pressure pump inlet chamber 2| communicating `with the opposite side of the planet pinion teeth through passages 22. The sun gear I5, as shown, is freely journalled between the plates I8 and I 'I for free rotation. The unit as soltar described is substantially similar to .that more particularly disclosed and claimed in my copendingapplication, Serial No. 420,479 led ent lo. 2,371,227,

A motor body 23 is connected to the endplate I1 of-the gear pump which is in turnconnected to the driven shaft II and is formed with a plurality of cylindrical bores 2| in annular array aground the 'driven shaft II and parallel thereto. Pistons 2 are slidable in the bores and have connectin rods 28 connected thereto through ball and s ket joints.

A sleeve 21 lies within the motor body coaxial with'the driven shaft and terminates ina valve plug 28 adjacent the end plate Il. The chamber I8 is adapted to communicate with the cylinders through a motor inlet groove 29 xtending subnstantially half way around th alve body/ and establishing communication between rthe chamber Il and the cylinders through .motor inlet Ports in the cylinderl side walls adjacent the end thereof. As shown, the motor inlet ports 3| may be made substantially the full width of the cylinders to' provide unrestricted communication between passage Il and the cylinders. Fluid is adapted to be vexhausted from the cylinder through motor exhaust passages 32 in the valve body 28, th'e exhaust passages extending through-v end walls II and through a Imatingflange on the driven shaft II-by means of which the driven shailtlis` connected to the gear carrier.

November 26, 1941, now Patl 'l A Figure 1 is a longitudinal 'section with the mopump through ports 33 extending through the To prevent damage in the 'event of overloading,l l

a relief port` 34 may be provided in the valve body 28 controlled by apressure responsive valve to establish communication between the motor inlet port 29` and the pump inlet passage 2|. In order that the transmission may be/throwri out of oper` ation to interrupt the torque between driving and I4 and I5 will turn relative to each other.

of the swash plate. l The driven shafts a by-pass 35 is provided extending between the motor inlet passage 29 and the interior of the sleeve 21. The passage 35 is normally closed by a tubular valve 33 tting closely within the sleeve 21 and overlying the by-pass 35. If it is desired to interrupt the torque ow the tube may be shifted to the left through a collar 31 to bring a port 33 in the tube into register with the by-pass 35. At .this time the motor inlet passage is vented directly to the interior of the sleeve so that no pressure will be built up in the cylinders or in the pump.

The sleeve 21 carries a swash plate 39 pivoted thereto about an axis 4| Itransverse to the driven shaft I|` and displaced from the axis thereof. The swash plate is urged to a radial position by a spring 42 acting between the swash plate and an abutment 43 and is adapted to yield in response to pressure thereon. If desired, one or more weights 44 may be connected to the swash plate so that it will tend to move into a radial position in response to centrifugal force.

A ring 45 is rotatably and slidably carried by the swash plate through bearings 46 sl'idable between the back surface of the ring and a. flange plate 41 thereon. Through the bearings 46 the ring vmay rotate freely on the swash plate and may slide over the interior bearingring to move radially relative to the swash plate. The ring 45 is connected to theopposite ends of the piston rods 2i through ball and socket joints and is adapted to be connected to the motor body to transmit torque thereto. For this purpose the motor body is formed with a tubular extension 43 rotatably surrounding the sleeve 21 and'carrying at its outer end a partially lcylindrical hub 49.. 'I'he cylindrical surfaces of the hub 49 are concentric with the ring 45 and are connected thereto by balls riding in registering grooves fin adjacent surfaces. This construction provides a constant velocity universal joint which may be of the type more particularly described and claimed in my copending application, Serial No. 424,390, filed December 26, 1941, now Patent No. 2,322,570. It will be noted that with this construction the ring 45 swings about a center intersecting the axis of the driven shaft while the swash plate 39 swings about the center 4| so that as the angle of the swash plate is changed the ring will have a sliding movement relative thereto.

The sleeve 21 is adapted to form the reaction plate tending to turn it rearwardly will be taken through the one-way brake 52 and forward torque the ring 45. As the driven shaft turns, the cyl.

inders communicating with the motor inlet passage 29 will move around into communication with. the motor outlet Lports 32 and liquid therein will flow back into the inlet passage 2| of the pump. During this operation the parts I2 and or fulcrum'member for the transmission and for ring gear I3 and if the gear carrier formed by the plates I 3 and I1 is held against rotation or is 'caused to rotateslower than the driving shaft by resistance on the driven shaft, the gears I3.

'I'his tends to turn the driven shaft through the carrier and will caus liquid such as oil to be pumped from theq pump inlet passage 2| into thel cham- -ber I3 and the oil will ilow through the motor inlet port 29 into all of the cylinders lying on the left sid of the transmission as seen in Figure 2. This will cause a thrust on the connecting rods 23 of these cylinders tending to tilt the swash" mplatei39 Vabout its pivot and to move thevring 45 in a forward direction dueto the camming action reaction on the Swash I3 turn with the driving shaft I0, the parts I6, I1, 23, 45, 49 and 49 turn with the driven shaft I I, and parts 21 and 28 are either held stationalir by the one way brake or turn forward when the brake overruns.

As the required output torque decreases, thev load on spring 42 decreases, the compression therein moves swash plate 39 to an angle more normal to the shaft 'I'his reduces the stroke of the-fluid motor, therefore, reduces its volumetric capacity, causing the motor to turn faster for a given v olume being pumpedl The volume pumped by the gear pump also decreases per revolution of the driving shaft I0 as the output shaft turns faster but not until the speed of the output shaft has been increased.

If the torque on the driven shaft becomes equal to that of the driving shaft the swash plate vwill assume a radial position at right angles to the driven shaft so that the pistons 25 will not be moved as the motor body rotates. At this time, the pump operates as a lock unit transmitting torque between the driving and driven shafts at a one to one ratio. Also, since there is no reaction to be absorbed by the one-way brake 52 it will tend to overrun allowing the sleeve 21 and the valve bodyA 28 to turn with the motor body. Thus, at this time all parts turn as a unit.

If it is desired to disconnect the driving and driven shafts the tube 36 may be shifted to the left to open the by-pass 35. With the driving shaft turning uid will be pumped freely from the pump outlet passage I8 through the port 29, by-pass 35, ports 33, and back to the inlet passage 2| of the pump. Thus no torque will be transmitted and the valve 36 performs all of the functions of the usual clutch.

Performance o f one unit embodying the invention is indicated by the following chart, assuming an engine R. P. M. of 100, an engine torque of and a pump designed to deliver 10 cubic inches I per differential revolution:

il #2 #3 #4 l #6 difference torque re- #5 #5x10 R P M between quite #3 required torque ot'driven' speeds oI the motor vol. per ratio shaft pump input which is #2 rev. oI and output alsoreaction motor members 6:1 16.6 83. 3 500 5 50 5:1 20 80 400 4 40 4:1 25 v'15 30o 3 so 3:1 33. 3 '66. 6 200 2 20 2:1 50 50 100 l l0 l. 5:1 66.6 33.3 50 M 5 1:1 100 0 0 0 0 While one embodiment of the invention has been shown and described in detail, it will be understOOd that thisvvembodiment is' illustrative only s and is not intended as a denition of the scope o f the invention, reference being had for this purpose to the appended claims.

What is claimed is:

l. A transmission for connecting andriving shaft to a driven shaft comprising a uid pump having two relatively rotatable elements, one of which is connected to the drivingshaft to be driven thereby and the other of which is connected to the driven shaft, a motor bodyconnected to the driven shaft' and having a plurality of cylinders therein parallel to the driven shaft,

pistons in the cylinders, a sleeve rotatably mounted around the driven shaft, valve means carried 'by the sleeve to control the inletpf fluid 'from the pump to the motor and the exhaust o1' uid from the motor, a swash plate pivoted to the sleeve, a ring rotatably carried bythe swash plate and connected lto the pistons to take the thrust fthereof, and a one-way brake to hold `the sleeve against reverse rotation.

2. A transmission for connecting a driving shaft to a driven shaft comprising a fluid pump having one element connected to the driving shaft and Aa. secondA em nt connected to the driven shaft to exert tional to`uld resistanc in the pump, a motor body connected to said s ond element and having a plurality of cylinders therein parallel to the driven shaft; pistons in the cylinders, 'a swash plate rotatably mounted around the driven shaft, means pivotally mountingthe swash plate on an axis transverse to the driven shaft and displaced from the driven shaft axis, yielding means urging the swash plate to a position at a right angle to the driven shaft, a ring rotatably and slidably carried by the swash plate and.F connected to the pistons to take the thrust thereof, .a universal :loint coaxial with the driven shaft connecting the ring to the motor body, and means to hold the swash plateagainst reverse rotation.

3. A transmission for connecting .driving and,

rque thereon propor- 3 porting the swash plate forpivotal movement, means to control the angular position of the swash plate about its pivot, means connecting thepistons to the swash plate, a. fixed member, and meansiconnecting the swash plate to the fixed member to prevent rotation thereof.

5. Atransmission forconnecting driving and driven shafts comprising a planetary. gear set, means encasing the gears of the set to forma iluid pump, means connecting one element of the gear set to the driving shaft and another element to the driven shaft,` a uid motor body connected to said other element of the gear set and having a plurality of -cylinders therein parallel to the drivenshaft. pistons in the cylinders, a sleeve coaxial with the drivenshaft and rotatable relative to the motor body, the sleeve being formed with valve means to control ow of uid between the pump and the motor, a swash plate pivoted -on the sleeve, means to control the angular podriven shafts comprising a planetary gear' set,

the swsh driven shafts comprising a planetary gear set having a cage for the planet gears, means encasing the gears of the set to form a plirality of duid pumps connected in multiple, means connecting the ring gear of the gear set to the driving shaft, means connecting the planet cage 'to the driven shaft to transmit al portion of the driving torque directly to the driven' shaft, a fluid motor body connected to said cage and having a plu'ality of cylinders therein, pistons in the cylin ers. a sleeve coaxial with the driven shaft and rotatable relative to the .motor body, the sleeve being formed with valve means to control flowof fluid between the pumps and the motor, a swash plate pivotally connected with the sleeve, means to control the angular position of the swash plate, means connecting the pistons to the swash plate, a xed member, and means connecting the swash plate and fixed member to prevent rotation of the swash plate. V

C 4. A transmission for connecting driving and vdriven shafts comprising a planetary gear set 65 having a cage for the planet gears, v'means encasing the gears of the set to form a plurality of iiuid pumps connected in'multiple, means connecting the ring gear of the gear set to the driving shaft, means connecting the planet'cage to the driven shaft to transmit a portion of the driving torque directly to the driven shaft, a fluid motor body connected to saidcage and having a plurality of cylinders therein, pistons in the cylinders, valve means to control the flow of fluid between the means encasing the gears of the-'set to form a :duid pump, means connecting one element of the gear set to the driving shaftand another element to the driven shaft, a fluid motor body connected to said other element of the gear set and having a plurality of cylinders therein parallel to the driven shaft, pistons in the cylinders, a sleeve coaxial with the driven shaft and rotatable relativoV to the motor body, the sleeve being formed with, valve means to control ow of fluid between the pump and the motor, a swash plate'pivoted on the sleeve, means to control the angular position of plate, a ring rotatably carried by they swash plate and connected tothe pistons, a universal joint connecting the ring to the motor body, a one-Lway brake to hold the sleeve against reverse rotation, the sleeve being formed with a bypass from the inlet to the exhaust side of the motor, and a valve member slidable rlongitudinally of the sleeve to control theby-pass 7. A transmission for connecting driving and means encasing the gears of the set to form a vfluid pump, means connecting one 'element of the gear set to the driving shaft and another element to the driven shaft, a uid motor body connected to said other element of the gear set and having Y a plurality of cylinders therein parallel to the driven shaft, pistons in the cylinders, a sleeve coaxial with. the driven shaft and rotatable relative to the motor body, the sleeve beingformedwith valve means to control ow of uid between the pump and the motor, a swash plate pivoted on the T sleeve on an axis transverse theretoA and displaced from-the axis thereof, resilient means urging the swash plate to a position' at a right angle to the sleeve, a ring rotatably and slidablycarried by the swash plate and connected to the pistons, a v universal joint ycoaxial with the .sleeve connecting theJ ring to the motor body, and a one-way brake to hold the sleeve against reverse rotation.

8. In a fluid transmission, a fluid motor comprisinga` motor body having a plurality of cylinders in annular array around a shaft, pistons in the cylinders, a swash plate mounted for pivotal gnovement about an axis transverse to and disaced from the axis of the shaft, yielding means Pumps and' th motor, a swash plate, means Sup- 75 urging the swash plate to 'a position at right anring, and a universal Joint coaxial with the shaft connecting the ring to the motor body.

9. In a fluid transmission, a fluid motor comprising amotor body having a plurality o1' cylin- I ders in annular array around a shaft, pistons in the cylinders, a swash plate mounted for pivotal movement about an axis transverse to and displaced irom the axis of the shaft. yielding means urging the swash plate to a position at right angles to the shaft, a ring rotatably and slidably carried by the swash plate, connecting rods jointed at their opposite ends to the pistons and the ring, a l5 to open and close the byfpass.

tubular extension on the motor body coaxial with the shaft and extending into the ring, and a universal Joint concentric with the ring connecting the ring to said extension.

10. In a fluid transmission, a body formed with a plurality of cylinders in annular array around an axis, a valve sleeve coaxial with the axis and formed with peripheral inlet and exhaust passages, the exhaust passages communicating with the central portion of the sleeve the cylinders 10 having ports in their side walls to register with said passages, means to produce relative rotation between .the body and the sleeve, the sleeve being formed with a by-pass from its inlet passage to its central portion, and a tube slidable in the sleeve ADIEL Y. DODG. 

